CVE-2025-24844

Executive Summary

CVE-2025-24844 is a Denial of Service (DoS) vulnerability affecting OpenHarmony versions up to and including v5.0.3. The flaw resides in a missing release of memory, allowing a local attacker with low privileges to exhaust system resources and cause a denial of service condition. The vulnerability has a low CVSS score of 3.3 due to the requirement for local access and the limited impact on availability. No public exploit code or proof-of-concept is currently available, and the patch status remains unknown.

Supply Chain & Package Security

This vulnerability affects the OpenHarmony operating system, an open-source project. The lack of a confirmed patch and the nature of the flaw (memory leak) could impact downstream distributions and devices that integrate OpenHarmony. Organizations using OpenHarmony in embedded or IoT devices should monitor for patch releases and consider the risk of local DoS attacks.

CVSS Breakdown & Threat Level

• CVSS Score: 3.3 (Low)
• Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
• Attack Vector: Local (AV:L) – The attacker must have local access to the system.
• Attack Complexity: Low (AC:L) – No special conditions are required.
• Privileges Required: Low (PR:L) – The attacker needs basic user-level privileges.
• User Interaction: None (UI:N) – No user action is required.
• Scope: Unchanged (S:U) – The vulnerability does not affect other components.
• Confidentiality Impact: None (C:N) – No data exposure.
• Integrity Impact: None (I:N) – No data modification.
• Availability Impact: Low (A:L) – The system may experience reduced performance or temporary unavailability.

Threat Level: Low. The requirement for local access significantly reduces the attack surface. However, in multi-user environments or systems where local users are not fully trusted, this could be exploited to degrade system performance.

Deep Dive & Mechanics

The vulnerability is a classic memory leak (CWE-401: Missing Release of Memory after Effective Lifetime). In OpenHarmony v5.0.3 and prior, a local attacker can trigger a scenario where allocated memory is not properly freed after use. Over time, repeated exploitation exhausts available memory, leading to system slowdowns or crashes.

The exact vulnerable component is not specified in the CVE description, but it likely resides in a system service or kernel module that handles user requests. The attacker would repeatedly invoke a specific system call or API that allocates memory without releasing it, causing the memory leak.

Vulnerable vs. Patched Code

Since no patch details are available, a direct code comparison cannot be provided. However, the fix would typically involve ensuring that all allocated memory is freed in all code paths, especially error handling and cleanup routines.

Vulnerable Code Pattern (Hypothetical):

void vulnerable_function() {
    char *buffer = malloc(1024);
    // ... process data ...
    // Missing free(buffer) before return
}

Patched Code Pattern (Hypothetical):

void patched_function() {
    char *buffer = malloc(1024);
    if (buffer == NULL) {
        return;
    }
    // ... process data ...
    free(buffer);
}

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Local access to an OpenHarmony system (v5.0.3 or earlier).
• Low-privilege user account.

Exploitation Steps:

1. Identify the vulnerable service or system call that causes the memory leak.
2. Write a script that repeatedly invokes this service/call in a loop.
3. Monitor system memory usage (e.g., using free or top).
4. Continue the loop until memory exhaustion causes a denial of service.

Example Script (Bash):

#!/bin/bash
# Hypothetical exploit for CVE-2025-24844
# Replace with actual vulnerable command
while true; do
    # Invoke the vulnerable system call
    /system/bin/vulnerable_command
done

Blue Team (Detection & Defense)

Detection:

• Monitor for unusual memory consumption patterns.
• Use system monitoring tools to track memory usage per process.
• Look for repeated invocations of specific system calls or services.

Defense:

• Apply patches as soon as they become available.
• Restrict local user privileges where possible.
• Implement resource limits (e.g., ulimit) to prevent a single user from exhausting memory.
• Use memory leak detection tools during development and testing.

Indicators of Compromise (IOCs)

• System Logs: Repeated entries indicating memory allocation failures.
• Memory Usage: Gradual increase in memory consumption over time, not released after process termination.
• Process Behavior: A specific process (e.g., vulnerable_service) consuming increasing amounts of memory.
• Performance: System slowdowns, application crashes, or out-of-memory (OOM) killer activations.

Detection Engineering

YARA Rule

rule CVE_2025_24844_Memory_Leak {
    meta:
        description = "Detects potential exploitation of CVE-2025-24844 memory leak in OpenHarmony"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2025-24844"
    strings:
        $s1 = "malloc" nocase
        $s2 = "free" nocase
        $s3 = "vulnerable_command" nocase
    condition:
        all of them
}

Sigma Rule

title: CVE-2025-24844 Memory Leak Exploitation Attempt
id: 12345678-1234-1234-1234-123456789abc
status: experimental
description: Detects repeated invocations of a vulnerable command leading to memory exhaustion
author: Valters IT
date: 2025-04-10
logsource:
    category: process_creation
    product: linux
detection:
    selection:
        Image|endswith: '/vulnerable_command'
        CommandLine|contains: 'loop'
    condition: selection
falsepositives:
    - Legitimate repeated use of the command
level: medium

Suricata Rule

alert ip any any -> any any (msg:"CVE-2025-24844 Memory Leak Exploitation"; content:"vulnerable_command"; nocase; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Restrict Local Access: Limit the number of local users and their privileges.
2. Resource Limits: Configure ulimit to restrict memory usage per user.
3. Monitor: Implement monitoring for unusual memory consumption patterns.

Long-Term Fix:

• Apply the official patch from OpenHarmony when released.
• Update to a patched version (e.g., > 5.0.3) once available.
• Conduct a code review to identify and fix memory leaks in the codebase.

Workarounds:

• If the vulnerable component is identified, disable or restrict access to it.
• Use memory leak detection tools (e.g., Valgrind) during development.

Valters IT
DevSecOps & Cyber Threat Intelligence Expert